Synthetic paint brush bristles have been made for many years and from various materials, including, most importantly, polyester and nylon. While very good paint brush bristles are made from the commonly used materials, two significant problems continue to exist: the first is that many of the best materials, such as nylon 6/12, are simply too expensive for all but the finest and most expensive paint brushes; the second is properties of the commonly used materials do not, in general, make the best bristles in all regards, and there is a need to provide a composition, at a relatively low cost, which will provide paint brush bristles of excellent quality.
Specifically, the paint brush industry has become highly sensitized to certain characteristics of the bristle which can improve bristle energy (bristle "snapback"), straightness, better registration and size control, improved tipability, and softness of the tips after the finishing operation. Nylon 6.12 is the generally accepted base material for nylon paint brush bristles throughout the industry; however, the 6/12 resin price increases in the past several years have created a dire need for a more price competitive nylon, especially in the middle and low end brush lines.
On the other hand, nylon 6/6 is generally not used as a paint brush bristle due to its high inherent curl and poor finish characteristics. This is particularly true of the hollow bristle, both tapered and untapered, which constitute the major quantity of bristles used today.